The present invention concerns a test block intended to be implanted in the circuit connecting an apparatus to be tested, in particular an electricity meter or a protective relay, and a power source, in particular an intensity sensor and/or a voltage sensor, supplying the apparatus to be tested, the test block comprising, on the one hand, a base including a plurality of inner electric circuits capable of allowing the transmission of information from the power source to the apparatus to be tested, on the other hand, a protective cover intended to be removably assembled with the base in order to form a closed enclosure in which the inner electric circuits are housed, the base and the protective cover being configured so that the removal of the protective cover gives access to a receiving site delimited by the base and capable of receiving by plugging a test plug independent of the test block and electrically linked to a test equipment, in particular a voltmeter and/or an ammeter and/or a dummy current source.
For several decades, It is known to implant an electric apparatus known as <<test block>> or <<test connector>> in the electric circuit which connects an apparatus to be tested to the power source which supplies the apparatus to be tested. By way of example, the Applicant commercializes test blocks of this nature under the trade name <<Essailec>>.
Usually, the power source can comprise a voltage sensor and/or an intensity sensor associated with a determined phase of an electric network while the apparatus to be tested can be an electricity meter or a protective relay intended to control at least one circuit breaker likely to act on said phase in case of overvoltage and/or over-current detected by the power source and the protective relay.
Conventionally, the test block comprises a base and a protective cover removably assembled on the base in order to delimit a closed and sealed enclosure according to the standard IP40 when the cover is fastened on the base. The enclosure encloses and protects a plurality of inner electric circuits independent of each other.
On a rear face and/or on a lateral face of the base, the test block comprises a plurality of input sockets allowing linking the inner electric circuits to the power source: each input socket is linked to a single determined inner electric circuit and each inner electric circuit is linked to a single input socket. It is necessary to connect a plurality of connectors in the input sockets and themselves linked to the power source by a cable comprising a plurality of independent conductor strands.
The test block also comprises a plurality of output sockets arranged on the rear face and/or on a lateral face of the base. These output sockets allow linking the inner electric circuits to the apparatus to be tested according to an arrangement in which each output socket is linked to a single inner electric circuit and each inner electric circuit is linked to a single output socket. It is necessary to connect a plurality of connectors to the output sockets and themselves linked to the apparatus to be tested by a cable comprising a plurality of independent conductor strands.
The removal of the protective cover, on the side of the of the front face of the base, gives access to a receiving site delimited by the base and capable of receiving, by plugging, a test plug independent of the test block and electrically linked to a test equipment. Usually, the test equipment may comprise a voltmeter and/or an ammeter and/or a dummy current source. The plugging of the test plug has the effect of acting temporarily on the state and/or the configuration of all or part of the inner electric circuits in a predetermined manner, depending directly on the design of the test plug, allowing carrying out measuring or calibrating operations relative to the apparatus to be tested by means of the test equipment. The test plug comprises actuating elements, configured for this purpose, capable of acting on all or part of the inner electric circuits in an appropriate manner depending on the operation to be carried out.
If the solutions currently implemented are satisfactory in terms of efficiency and robustness, they are not fully satisfactory, after all, in terms of ease of implementation, reliability and quality of measurements and calibrations, or sometimes even safety.
Indeed, the new current and voltage sensors likely to be used at the power source have increasingly low output values in voltage and/or in current. These values are therefore increasingly sensitive to the electromagnetic disturbances generated by the cabinets and also by the environment of the cabinets.